Hi! I'm new on this wonderful forum, I'm writing from Italy and I'm going to install on my lovely C124 3.0 24v 104980 a "Rotrex" C30/94 supercharger....

I'm not a professional mechanic, only amateur, this will be a big adventure for me...
I've found other similar threads but It seems not specifically for the .980.

I've the charger,oil cooler, a Mishimoto intercooler, bracket,Tial Bov and some other things.
My idea is to arrive at 300/320hp for the moment.

The big question is: Is it possible with stock injectors?
We're talking about the Bosch mechanic injectors.
I thought to find bigger injectors somewhere but It seems to be very difficult to do...

try Everybody needs TURBINA! for parts.About $6500 usd for a good kit.

__________________
1999 w140, quit voting to old, and to old to fight, a god damned veteran

Thank you,
I know this solution but I've decided for the supercharger solution, I own 80% of what I need.They sell only EFI kit, I want to use the original ECU with stock or bigger injectors.

Injectors don't determine fuel flow in a CIS system, that's the job of the fuel distributor. The injectors are just glorified misters. That said the 104.980 fuel distributor is good for just over 300hp, IIRC.

The big issues you are facing is the need for fuel enrichment during boost, and the need for timing retard during boost as well. Neither are accounted for easily with the stock equipment and without both, broken rings and ring lands are a near certainty.

When I was boosting CIS I used an MSD boost timing master to pull timing for boost, but it was very limited in how it worked. I also had an original Mosselman boost fuel controller, but those are a lot rarer than hen's teeth, so forget I mentioned it.

My eventual solution was to swap CIS for a fully programmable EFI with integrated spark control, ALA Megasquirt. In doing so I went from being able to run 9 PSI to running 19PSI. Not to mention I just passed my state's emissions test two weeks ago.

__________________

90 300TE 4-M
Turbo 103, T3/T04E 50 trim
T04B cover .60 AR
Stage 3 turbine .63 AR
A2W I/C, 40 LB/HR
MS2E, 60-2 Direct Coil Control
3" Exh, AEM W/B O2
Underdrive Alt. and P/S Pulleys,
Vented Rear Discs, .034 Booster.
3.07 diffs 1st Gear Start

90 300CE 104.980
Milled & ported head, 10.3:1 compression
197° intake cam w/20° advancer
Tuned CIS ECU
4° ignition advance
PCS TCM2000, built 722.6
600W networked suction fan
Sportline sway bars
V8 rear subframe, Quaife ATB 3.06 diff

As said around 300hp is about what that cis will run safely. Maybe a bit more. I ran a hob switch to switch to full throttle enrichment when going into boost. And made a small adjustment to the eha for more fuel. That is a very delicate adjustment though. More than one throw away eha to get it right.
Also that is with all good near new quality working parts. Which these days cost more than an aftermarket fuel injection system.

Ok, thanks for your reply.
My intention now is to mount all the parts and try to work with original Cis without problems.

How much psi you recommend to start?
In wich conditions I've to measure this value?
Also with low pressure I need to retard timing during boost?
My God I would ask so many things...

Boosted engines need enrichment for boost and less timing. You're asking what can you get away with. Answer: anything until the engine breaks.

The engine that my Mosselman controller came from ran 6 PSI with fuel enrichment and stock timing. It broke several rings when the ring lands collapsed. Good for me because I bought it cheap as a parts car.

Best advice I can give is to sit on your parts until you can pull timing and add fuel.

Old saying: Good, cheap, or fast.... pick two.

__________________

90 300TE 4-M
Turbo 103, T3/T04E 50 trim
T04B cover .60 AR
Stage 3 turbine .63 AR
A2W I/C, 40 LB/HR
MS2E, 60-2 Direct Coil Control
3" Exh, AEM W/B O2
Underdrive Alt. and P/S Pulleys,
Vented Rear Discs, .034 Booster.
3.07 diffs 1st Gear Start

90 300CE 104.980
Milled & ported head, 10.3:1 compression
197° intake cam w/20° advancer
Tuned CIS ECU
4° ignition advance
PCS TCM2000, built 722.6
600W networked suction fan
Sportline sway bars
V8 rear subframe, Quaife ATB 3.06 diff

What you say discourage me a little...

Also with 5 psi, retarding 2/3 degrees the timing and using 98 octane gasoline?

I know it's discouraging and I'd love to see you pull it off. I've got a 104.980 in addition to my turbo 103. I haven't touched the motor yet. Been slowly working on getting the chassis and driveline capable of handling big power so I too am waiting until I can afford to build it right.

Ok guys,
Other solution:
I've installed on the car an LPG plant with its injectors etc. I could use the LPG with gasoline injectors supporting.
It should not be so ardous: When you drive on LPG the gasoline pump is in operation with minimum pressure so the gasoline return in the tank because there isn't enough pressure to open the injectors, this is what normally happen if you don't fit the "stop/pump".
Now, when the ecu finds a poor mixture the eha increase pressure and so you have enrichment, (this is what I believe).
I think it's possible,I should ask the LPG technician how to programm LPG ecu.

Sweet. LPG sounds like the go.

You may need to blow through a GasResearch carby, I think the vapour injection gas computers require a factory ECU to base their operation from.. And yours is a mechanical injection system yes?

Then, put a water to air intercooler in it, and circulate the water through the gas convertors, into the intercooler. Isolate the system from the main engine cooling system with some taps, OR just plumb it seperately.

You'll end up with boosted air temps 20ish degrees lower than ambient temps. (whatever 10 degrees celsius works out as) If the convertors ice up, add a front mount heat exchanger in front of the rad/ac heat exchangers to heat the water up a little, this should fix the icing problem, if it exists. Use two convertors too, as when you dont heat them with engine coolant, they flow less.

You can even tap that, so in summer, leave the heat exchanger out of the system, and in winter, turn it back on.

Water injection (just a little bit) is good for GAS, I prefer to do it between the intercooler and the manifold, because in cold weather with that setup, the water can freeze and block the intercooler up, and when it thaws, water runs into your engine. Not a good thing. Although the dip in the plenum on the M103-style manifold holds a bit of water before you give it a big twist ...

We've had intake air temps, at 18psi boost, below freezing. Serious. -7 degrees C one cold night. Yes, at 18 psi. I am not sure petrol would even work at these air temps, as it goes in as a liquid, and only the vapour ignites. E85 might work though. I will be trying that later in the year I hope. I think we were running 38 degrees of ignition advance too.

Oh, and one more thing..... Make sure you use anti-freeze. Very important!!

You'll likely need some form of ignition control, I love those MSD6BTM's, but they only retard, they are not programmable. Likely you'll want 16 degrees initial, 28 degrees final, maybe 4 degrees vac advance, and all in by maybe 2500 as a base line. Maybe give it a go without the BTM or whatever you decide first. You'll need 2 ranges colder spark plugs (to start) and close the gap up, to maybe .034, if you have ignition problems.

Using the latent heat of evaporation of Propane to chill an A2W IC..... Brilliant. Absolutely. Brilliant.

__________________

90 300TE 4-M
Turbo 103, T3/T04E 50 trim
T04B cover .60 AR
Stage 3 turbine .63 AR
A2W I/C, 40 LB/HR
MS2E, 60-2 Direct Coil Control
3" Exh, AEM W/B O2
Underdrive Alt. and P/S Pulleys,
Vented Rear Discs, .034 Booster.
3.07 diffs 1st Gear Start

90 300CE 104.980
Milled & ported head, 10.3:1 compression
197° intake cam w/20° advancer
Tuned CIS ECU
4° ignition advance
PCS TCM2000, built 722.6
600W networked suction fan
Sportline sway bars
V8 rear subframe, Quaife ATB 3.06 diff

HAHA!!
They didn't think so on OZBENZ - they kicked me off for it...

Hey, there's an awesome car, an m103 4matic wagon, with a turbo!! I have been looking for one of them in Australia for quite a while... ( minus the turbo, of course) A sedan would do too....

Sorry in advance for the thread de-rail.

Hold out for the 4-M wagon. There is something magical about that combo. It was second only to the Cossie in terms of handling in those years of MB cars.

Hi,

kiqnkf What you say is a very fine possibility to realize later for to increse boost.

On my C124 there is installed one of the few sequential LPG system running, with electonic injectors and a dedicated ECU that works togheter with original MB ECU. It works fine and I'm sotisfied.


Now I've to decide wich solution is better for me in order to have an every day car with circa 100hp more than original.
I tought to do this conserving original CIS fuel system and LPG System but it seems to be dangerous for the engine.

I've a new Rotrex C30/94 ready to be installed, dismounted the AC (that was down for a leak that I can't find) to have more space, designed and build the bracket that will go above the alternator, find an air/air intercooler to put where AC radiator was before. Also the oil cooler will be positioned forward the intercooler.
In these days I'm desperately looking for a rigid air inlet elbow to connect on the MAF like the TurboTechnics one (any suggestions?).

I've decided for supercharger solution because it seems to me to be less invasive and simply for me inasmuch I'm not a professional mechanic...

You said that I need to enrich and control the timing. That is now what I want to do.
I've asked for a solution to DiYautotunes explaining also that I've an LPG system to control and they responded propmtly to me.
The suggested me the MS3Pro that is their newest product.
What do you think about?
TURBOBANDIT has his M104kit with MS3.
Than I need new fuel Injectors, A fuel rail, what else?

I appreciate any suggestions from you all.